Alt255,
I think your way is the best way for Winxx machines.
None of the low-level techniques work on the new Windows 32 environment. The most they do is close the DOS box. In the WinNT/2K environments, shutting down the computer may be disabled for a given account. In that case, there's no way to do it, as far as I know.
boot1:
DEF SEG = &H40
POKE &H473, 12 '0000 for cold boot
POKE &H472, 34
DEF SEG = -1: '-1==&HFFFF
CALL ABSOLUTE(0)
END
boot2:
OUT 100, 254
boot3:
SHELL "START"
boot4:
'int 19h using CALL INTERRUPT(&h19,regs,regs)
boot5:
OUT &H64, &H92